and many more benefits!

GMAT Club Timer Informer

Hi GMATClubber!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Show Tags

Updated on: 26 Oct 2018, 02:04

6

19

00:00

A

B

C

D

E

Difficulty:

35% (medium)

Question Stats:

71%(01:31) correct 29%(01:42) wrong based on 1673 sessions

HideShow timer Statistics

Cheever College offers several online courses via remote computer connection, in addition to traditional classroom-based courses. A study of student performance at Cheever found that, overall, the average student grade for online courses matched that for classroom-based courses. In this calculation of the average grade, course withdrawals were weighted as equivalent to a course failure, and the rate of withdrawal was much lower for students enrolled in classroom-based courses than for students enrolled in online courses.

If the statements above are true, which of the following must also be true of Cheever College?

(A) Among students who did not withdraw, students enrolled in online courses got higher grades, on average, than students enrolled in classroom-based courses.

(B) The number of students enrolled per course at the start of the school term is much higher, on average, for the online courses than for the classroom-based courses.

(C) There are no students who take both an online and a classroom-based course in the same school term.

(D) Among Cheever College students with the best grades, a significant majority take online, rather than classroom-based, courses.

(E) Courses offered online tend to deal with subject matter that is less challenging than that of classroom-based courses.

Show Tags

12 Jan 2018, 00:52

4

1

Here we have another inference question, so we don't have a conclusion with a well-structured line of reasoning. As always, make sure that you clearly understand the given information and pay attention to the details:

According to a study, the average student grade for OCs was the same as the average student grade for CBCs.

When calculating average grade for that study, course withdrawals were weighted as equivalent to a course failure.

The rate of withdrawal was much lower for CBC students than for OC students.

OC students were more likely to withdraw. In the eyes of the study, those students who withdrew failed the course. So before factoring in the students who did NOT withdraw, we are starting with a higher proportion of failure among the OC students. For example, if there were twice as many withdrawals from OCs as there were from CBCs, then we'd be starting with a failure rate that is twice as high among OC students as it is for CBC students (again, BEFORE factoring in the students who did not withdraw).

Now let's factor in the students who did NOT withdraw. Let's say that the average grade among OC students who did not withdraw was the SAME as the average grade among CBC students who did not withdraw. As stated above, there were more OC withdrawals. So if the non-withdrawal averages are equal and there are more OC withdrawals, then the overall average of OC students would have to be lower than the overall average of CBC students.

But we are told that this is not the case and that the overall averages are the same for both groups. Remember, when we are just looking at the withdrawals, we are starting with a higher failure proportion among OC students. In order for the average of the OC students to "catch-up" to the average of the CBC students, the average of the OC students who did NOT withdraw would have to be HIGHER than the average of the CBC students who did not withdraw. Otherwise, the CBC students would have a higher overall average.

Quote:

(A) Among students who did not withdraw, students enrolled in online courses got higher grades, on average, than students enrolled in classroom-based courses.

As described in the preceding analysis, choice (A) has to be true. Keep this one.

Quote:

(B) The number of students enrolled per course at the start of the school term is much higher, on average, for the online courses than for the classroom-based courses.

The study is concerned with AVERAGE grades, so we cannot determine anything about the actual number of students per course. Eliminate (B).

Quote:

(C) There are no students who take both an online and a classroom-based course in the same school term.

The study compares average student grade for OCs to average student grade for CBCs. This study could be conducted even if some students took both types of courses. The study would simply include the student's OC grades in the OC average and include the student's CBC grades in the CBC average. So we might have students who took both types and we might not. (C) cannot be determined.

Quote:

(D) Among Cheever College students with the best grades, a significant majority take online, rather than classroom-based, courses.

As with choice (B), the findings involve AVERAGE grades. It is certainly possible that a large portion of the students with the BEST grades took CBCs. As long as the AVERAGE of OC students who did not withdraw was higher than the AVERAGE of the CBC students who did not withdraw, it doesn't matter which group has the students with the BEST grades. For example, it is possible that the 10 best students all took CBCs, the rest of the CBC students did poorly, and most of the OC students did fairly well.

Choice (D) might be true, but we don't know for sure. And we certainly cannot determine that a significant majority of the students with the best grades took OCs rather than CBCs. Eliminate (D).

Quote:

(E) Courses offered online tend to deal with subject matter that is less challenging than that of classroom-based courses.

The information in the passage does not offer any evidence to EXPLAIN the data. All we can determine is that the average of the OC students who did NOT withdraw has to be higher than the average of the CBC students who did not withdraw. A number of factors could explain this result (better teachers, better courses, etc). Choice (E) is a possible explanation, but we cannot determine whether it is true based on the information in the passage. Eliminate (E).

Choice (A) is the only statement that HAS to be true.
_________________

Need an expert reply?Hit the request verbal experts' reply button -- and please be specific about your question. Feel free to tag @GMATNinja in your post. Priority is always given to official GMAT questions.

General Discussion

Show Tags

30 Sep 2013, 20:29

1

Cheever College offers several online courses via remote computer connection, in addition to traditional classroom-basedcourses. A study of student performance at Cheever found that, overall, the average student grade for online coursesmatched that for classroom-based courses. In this calculation of the average grade, course withdrawals were weighted asequivalent to a course failure, and the rate of withdrawal was much lower for students enrolled in classroom-based coursesthan for students enrolled in online courses. If the statements above are true, which of the following must also be true ofCheever College?(A) Among students who did not withdraw, students enrolled in online courses got higher grades, on average, than studentsenrolled in classroom-based courses.(B) The number of students enrolled per course at the start of the school term is much higher, on average, for the online coursesthan for the classroom-based courses.(C) There are no students who take both an online and a classroom-based course in the same school term.(D) Among Cheever College students with the best grades, a significant majority take online, rather than classroom- based,courses.(E) Courses offered online tend to deal with subject matter that is less challenging than that of classroom-based courses.

Show Tags

02 Oct 2013, 00:17

ankurjohar wrote:

Cheever College offers several online courses via remote computer connection, in addition to traditional classroom-basedcourses. A study of student performance at Cheever found that, overall, the average student grade for online coursesmatched that for classroom-based courses. In this calculation of the average grade, course withdrawals were weighted asequivalent to a course failure, and the rate of withdrawal was much lower for students enrolled in classroom-based coursesthan for students enrolled in online courses. If the statements above are true, which of the following must also be true ofCheever College?(A) Among students who did not withdraw, students enrolled in online courses got higher grades, on average, than studentsenrolled in classroom-based courses.(B) The number of students enrolled per course at the start of the school term is much higher, on average, for the online coursesthan for the classroom-based courses.(C) There are no students who take both an online and a classroom-based course in the same school term.(D) Among Cheever College students with the best grades, a significant majority take online, rather than classroom- based,courses.(E) Courses offered online tend to deal with subject matter that is less challenging than that of classroom-based courses.

Option A - iSAWT (I felt student who didnt withdraw got higher score is not right answer choice as the argument is only about the enrolled/withdrawl student count)

Hence, I marked option B as right choice.

Please help me in understanding what i am missing in making logical structure of this argument and in doing pre-thinking.

Thanks,Ankur

Hi Ankur,

You are correct in rejecting options C, D, and E as OFS.

However, the reasons for selecting option B and rejecting option A are correct.

First, let's talk about option B:

(B) The number of students enrolled per course at the start of the school term is much higher, on average, for the online courses than for the classroom-based courses.

Nowhere does the passage talk about number of students. The passage only talks about withdrawal rate, which refers to proportion of students who withdraw from the course. We do not know anything about the number of students in either traditional or online courses. So, option B is incorrect.

Coming to option A:

(A) Among students who did not withdraw, students enrolled in online courses got higher grades, on average, than students enrolled in classroom-based courses.

You are correct that the passage only talks about students who withdrew and not about students who did not withdrew. But what is the relation between students who withdrew and students who did not withdrew?

The relation is:

Students who did not withdrew + Students who withdrew = Total number of students enrolled

Now, we are given average grade for all the enrolled students and we also know average grade of Students who withdrew - the grade is "0" or "failed". From this, don't you think we can make some judgement about the average of students who did not withdrew.

We can!

If average grade for "all enrolled students" was same for traditional and online coursesAnd "Number of students who withdrew i.e. who got "Fail" grade" were higher for online courses than traditional coursesThen, in such a case, the average grade of students who did not withdrew must be higher for online courses than traditional courses.

Do you get it?

If you look back now, you can see that Students who did not withdrew and Students who withdrew constitute all the students. Right?

In such cases, where two sets constitute everything or the universe, then in a lot of cases, on the basis of information of one set, we can make inferences about the other set.

Show Tags

07 May 2014, 22:51

1

Cheever College offers several online courses via remote computer connection, in addition to traditional classroom-based courses. A study of student performance at Cheever found that, overall, the average student grade for online courses matched that for classroom-based courses. In this calculation of the average grade, course withdrawals were weighted as equivalent to a course failure, and the rate of withdrawal was much lower for students enrolled in classroom-based courses than for students enrolled in online courses.

If the statements above are true, which of the following must also be true of Cheever College?

(A) Among students who did not withdraw, students enrolled in online courses got higher grades, on average, than students enrolled in classroom-based courses.(B) The number of students enrolled per course at the start of the school term is much higher, on average, for the online courses than for the classroom-based courses.(C) There are no students who take both an online and a classroom-based course in the same school term.(D) Among Cheever College students with the best grades, a significant majority take online, rather than classroom-based, courses.(E) Courses offered online tend to deal with subject matter that is less challenging than that of classroom-based courses.

the average student grade for online courses = the average student grade for classroom-based courseswithdrawal= failurewithdrawal for online courses > withdrawal for classroom-based courses

so it can be deduced A : to have the same average with students in classroom-based courses, students in online courses should get higher grades on average to compensate the higher withdrawal.

D is not correct bcz in the argument we don't care about the best grades, higher grades is enough to justify the equation. consider the following scenario:

Show Tags

08 Jan 2018, 11:32

Cheever College offers several online courses via remote computer connection, in addition to traditional classroom-based courses. A study of student performance at Cheever found that, overall, the average student grade for online courses matched that for classroom-based courses. In this calculation of the average grade, course withdrawals were weighted as equivalent to a course failure, and the rate of withdrawal was much lower for students enrolled in classroom-based courses than for students enrolled in online courses.

If the statements above are true, which of the following must also be true of Cheever College?

(A) Among students who did not withdraw, students enrolled in online courses got higher grades, on average, than students enrolled in classroom-based courses. -Correct(B) The number of students enrolled per course at the start of the school term is much higher, on average, for the online courses than for the classroom-based courses. -We can't say anything about the number of students(C) There are no students who take both an online and a classroom-based course in the same school term. -Can't say(D) Among Cheever College students with the best grades, a significant majority take online, rather than classroom-based, courses. -Can't say anything about the "best" students. We just know about the "average".(E) Courses offered online tend to deal with subject matter that is less challenging than that of classroom-based courses. -Challenging? out of scope_________________

Show Tags

Cheever College offers several online courses via remote computer connection, in addition to traditional classroom-based courses. A study of student performance at Cheever found that, overall, the average student grade for online courses matched that for classroom-based courses. In this calculation of the average grade, course withdrawals were weighted as equivalent to a course failure, and the rate of withdrawal was much lower for students enrolled in classroom-based courses than for students enrolled in online courses.

If the statements above are true, which of the following must also be true of Cheever College?

(A) Among students who did not withdraw, students enrolled in online courses got higher grades, on average, than students enrolled in classroom-based courses.

(B) The number of students enrolled per course at the start of the school term is much higher, on average, for the online courses than for the classroom-based courses.

(C) There are no students who take both an online and a classroom-based course in the same school term.

(D) Among Cheever College students with the best grades, a significant majority take online, rather than classroom-based, courses.

(E) Courses offered online tend to deal with subject matter that is less challenging than that of classroom-based courses.

Every question of the day will be followed by an expert reply by GMATNinja in 12-15 hours. Stay tuned! Post your answers and explanations to earn kudos.

IMO - A

Option A - Correct answer; If classroom guys got less F than online course enrolled guys but still have the similar average grade, the guys who completed online course must have had better grades than classroom enrolled guys.B - Not necessary with given stem info.C - Irrelevant, no information providedD - Information is provided about the average grade, not the best grades. Also, no other information available about numbers of classroom students and remote course enrolled students.E - As per stem, we are talking about each course average grade comparison so out of scope.
_________________

Show Tags

18 Jan 2019, 17:24

Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________